Grinding machine



g- 1970 E. w. HILLIER ET 3,525,179

GRINDING MACHINE Filed Oct. 2, 1967 2 Sheets-Sheet 1 INVENTORS.

Q (S /mar fl/MY/fer 6 BY Weber/ff Wrof'fer ATTORNEYS Aug. 25, 1970 w, HILLIER ET AL 3,525,179

GRINDING MACHINE Filed Oct. 2, 1967 2 Sheets-Sheet 2 INVENTORS.

67/770" 4/ MV/lier f United States Patent US. Cl. 51-46 13 Claims ABSTRACT OF THE DISCLOSURE A grinding machine assembly of the type utilized for grinding twist drills including a grinding wheel and a drill holder. The drill holder includes a shaft which is oscillated through an are by an auxiliary electric motor so that when a drill is disposed in the holder it moves faster in one direction than the other during its one oscillation for grinding engagement with the grinding wheel. The auxiliary motor rotates a link having a slot therein and a roller is disposed in the slot to engage a rod extending from the shaft for oscillating the shaft. The roller may be moved or adjusted to different positions along the slot in the link for adjusting the arc of oscillation. There is also included means for providing a hesitation in the movement of the holder means as the latter is changing direction of movement while oscillating. Such a hesitation allows a drill to be indexed or a new drill to be disposed in the holder for grinding. In addition, the grinding wheel is reciprocated in a direction parallel to its axis of rotation by another auxiliary electric motor.

There are numerous grinding machines known in the prior art for sharpening twist drills and the like. Many of these grinding machines utilize a drill holder of special construction for moving the drill into grinding engagement with the grinding wheel. In most of these prior art assemblies the drill is manually disposed in the holder and the holder is manually moved to move the drill into grinding engagement with the grinding wheel. Normally during the sharpening operation the area of the end of the drill between adjacent flutes is ground during the movement of the holder and thereafter the drill is rotated or indexed to a position where the area between adjacent flutes is ground as the holder is manually moved. Although such manually operated assemblies have proven very satisfactory, their operation is somewhat ineflicient when suc cessively sharpening a number of various different drills.

It is often desirable and frequently necessary to successively sharpen drills of dilferent sizes, i.e., drills having different diameters. As different drill sizes are sharpened the peripheral grinding surface of the grinding wheel wears unevenly because of the different sizes of the areas of the ends of the drills being sharpened. Such wear frequently produces an unsatisfactory surface on the end of the drill and in addition requires frequent dressing or truing of the grinding wheel.

Accordingly, it is an object and feature of this invention to provide a grinding machine assembly for grinding twist drills and the like and including a power actuated drill holder means for successively moving drills into grinding engagement with the grinding wheel and moved in a manner to provide an improved ground surface on the drill and to allow the drills to be indexed and replaced in a very eflicient manner to maximize the number of drills which may be sharpened in a given period of time.

In correlation with the foregoing object and feature, another object and feature of the instant invention is to provide a means for providing a hesitation in the movement of the drill holder means as the latter is changing direction of movement while oscillating to provide the "Ice desired period of time for indexing drills and replacing drills in the holder.

Further in correlation with the above objects and features of this invention, another object and feature is to provide means for reciprocating the grinding wheel in a direction parallel to its axis of rotation for improving the ground surface on the end of the drills and to provide even wear of the grinding surface thereby reducing the dressing of the grinding surface.

Again in correlation with the foregoing objects and features of this invention, another object and feature is to include means to adjust the amount of movement in the oscillation of the drill holder to compensate for different drill sizes to maximize the operating efliciency of the machine.

In correlation with the foregoing objects and features, another object and feature of this invention is to provide a means for adjusting the length of the stroke of reciprocation of the grinding wheel to compensate for drills of different diameters.

Furtherin correlation with the above objects and features, another object and feature of this invention is to provide means for adjusting the length or period of the hesitation in the movement of the drill holder means.

Other objects and attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a plan view of a preferred embodiment of the instant invention;

FIG. 2 is a fragmentary cross-sectional view taken substantially along line 2--2 of FIG. 1;

FIG. 3 is a fragmentary cross-sectional view taken substantially along line 33 of FIG. 2;

FIG. 4 is a fragmentary cross-sectional view taken substantially along line 44 of FIG. 1; and

FIG. 5 is a view taken substantially along line 55 of FIG. 1.

Referring now to the drawings wherein like numerals indicate like or corresponding parts throughout the several views a preferred embodiment of the grinding machine assembly of the instant invention is generally shown at 10 in FIG. 1. The grinding machine assembly 10 is of the type utilized for grinding twist drills or the like and includes a grinding wheel 12 having a peripheral grinding surface and rotated about a first axis by the electric motor 14. There is also included drill holder means generally indicated at 16 for supporting a drill or the like and oscillatable to move a drill into and out of grinding engagement with the grinding surface of the grinding wheel 12. A first power means generally shown at 18 moves the holder means 16 faster in one direction than the other direction of oscillation, which will become more clear hereinafter.

There is also included a support structure comprising the table 20, a compound 22, the plate 24 and the upwardly extending flange 26. The flange 26 is welded or otherwise secured to the plate 24 and the plate 24 is supported on the compound 22 by bolts or the like which threadedly engage members disposed in T-shaped slots 28. The compound 22 is of the type well known in the art wherein the wheels 30 are utilized to adjust the position of the components of the compound so that the position of the flange 26 and the plate 24 is adjusted. The support structure also includes a tubular member 32 which is welded or otherwise secured to the flange 26.

The holder means 16 is rotatably supported by the tubular member 32 of the support structure for oscillation in an are by the power means 18. More specifically, the holder means 16 includes a shaft 34 which is rotatably supported by the tubular member 32 through the bearings 3 36. A drill support or chuck 38 is disposed at a first end of the shaft 34 and is attached thereto by the screw 40. Various drill holders or chucks may be utilized and it has been found satisfactory to utilize a drill holder of the type disclosed in U.S. Pat. 2,827,741.

A sleeve 42 is disposed on the second end of the shaft 34 and is secured thereto by a screw 44. The screw 44 comprises an adjustment means for selectively allowing the sleeve 42 to be rotated to a new position on the shaft 34 to adjust the length or period of the hesitation in the oscillation of the holder 38.

A rod 46 extends radially from the sleeve 42 and is secured thereto in an appropriate manner such as by welding, brazing or the like. A first auxiliary electric motor 48 is supported on the plate 24 by the bolts 50. A gear box 52 is attached to the electric motor 48. A shaft 54 extends from the gear box 52 and a first link 56 is rotated about the axis of the shaft 54 when the motor 48 is actuated. A roller 58 is attached to the first link 56 and engages the rod 46 to move the rod 46 through an arc. The link 56 has a slot 60 therein which extends radially relative to the axis of the shaft 56 and the roller 58 is adjustable along the slot 60 for adjusting the arc or the length of oscillation of the rod 46 and, hence, the shaft 34. The roller 58 is held in place by a stud 62 having a wing nut 64 thereon and the roller 58 may be moved along the slot 60 by loosening the wing nut 64.

There is also included an adjustable stop 66 attached to the shaft 34 by the screw 68 for limiting the rotation of the shaft 34 as illustrated in phantom in FIG. 5.

There is also included biasing means comprising the spring 70 for urging the shaft 34 to rotate in one direction, i.e., clockwise as viewed in FIG. 5.

As best illustrated in FIG. 5, the link 56 rotates in a counterclockwise direction about the axis of the shaft 54. The spring 70 biases the shaft 34 so that the rod 46 is always biased upwardly and into engagement with the roller 58. Assuming for the moment that the stop 66 does not contact the flange 26 to limit upward movement of the rod 46 whereby the roller 58 is always in contact with the rod 46, it will be seen that as the link 56 is rotating upwardly, as illustrated in FIG. 5, the rod 46 will rotate the shaft 34 faster in the clockwise direction as viewed in FIG. than in the counterclockwise direction when the roller 58 is moving downwardly. This faster oscillation of the shaft 34, and consequently the holder 38, in one direction is due to the fact that the roller 58 contacts the rod 46 closer to the axis of rotation of the shaft 34 when moving upwardly than when moving downwardly as viewed in FIG. 5.

In addition, when the roller 58 is at the top of its circle of movement it instantaneously moves in a direction which is tangent to the rod 46 thereby providing a slight hesitation in the rotation of the shaft 34 and hence the holder 38 when the latter are changing direction of movement while oscillating. In some instances, this amount of hesitation is sufiicient for a drill to be removed from the holder and the new drill inserted or for a drill to be indexed by rotating for the next grinding operation. If this period of hesitation is not sufficient, however, the adjustable stop 66 is positioned to engage the flange 26 to limit upward movement of the rod 46 so that the roller 58 disengages the rod 46 during the upper portion of its circular movement thereby providing a longer period of hesitation. These two features therefore define a means for providing a hesitation in the movement of the holder means as the latter is changing direction of movement while oscillating and the adjustable stop 66 defines an adjustment means for adjusting the length of the hesitation, i.e., the period of hesitation.

When the rod 46 is at its upper limit of movement, as illustrated in phantom in FIG. 5, the holder 38 is positioned so as to maintain a drill out of contact with the grinding wheel 12. As the rod 46 is moved downwardly the holder 38 is rotated so as to move the end of a drill into contact with the grinding wheel 12 for initial grinding of the drill. As mentioned above, this movement is slower than the movement in the opposite direction. During this slower movement the major grinding of the drill is accomplished. When the rod 46 moves upwardly from its lower position, as illustrated in FIG. 5, it moves faster than it is moved downward. During this faster upward movement of the drill, the drill is barely in contact with the grinding wheel but is in sufiicient contact for the removal of burrs from the drill and to provide a polish or finish on the drill. The oscillation of the holder 38 is again hesitated or momentarily stopped so that the drill may be rotated, i.e., indexed, or replaced with the next drill to be sharpened, such occurring as the machine remains in continuing operation.

Drills of different sizes, that is, drills having different diameters, have different amounts or areas to be ground and accordingly require different lengths of arcs of oscillation of the holder 38 for grinding thereof. In other words, a drill of a large diameter would require a larger arc of oscillation than a drill of a smaller diameter. Therefore, in order to most efficiently utilize the grinding assembly for various different sizes of drills, the roller 58 may be adjusted along the slot 60 in the link 56 to adjust the amount of movement in the oscillation, i.e., to adjust the length of the arc of oscillation. The roller 58 and the slot 60 therefore define a means to adjust the amount of movement in the oscillation.

As alluded to hereinbefore the electric motor 14 supports and rotates the grinding wheel 12. A support platform 72 is disposed on the table 20 and supports the rods 74. Brackets 76 support the electric motor 14 and are slidable along the rods 74. The rods 74 and brackets 76 comprise slide means for supporting the grinding wheel 12 for reciprocation parallel to its axis of rotation.

There is also included a second power means generally shown at 78 for reciprocating the grinding wheel 12. The second power means 78 includes a second auxiliary electric motor 80 and linkage means operatively interconnecting the electric motor 14 and the auxiliary electric motor 78 for reciprocating the electric motor 14 and, hence, the grinding wheel 12. More specifically, the linkage means comprises a second link 82 which is rotated about the axis of the shaft 84, with the shaft 84 extending from the gear box 86 and being rotated by the auxiliary electric motor 80. The linkage means also includes a third link 88 operatively connected at a first end by the pin 90 to the electric motor 14 and operatively connected at the other end to the second link 82. The link 82 has a slot therein which extends radially from the shaft 84 and a bolt extends therethrough with a wing nut 92 disposed thereon for securing the end of the link 88 to the link 82. The wing nut 92 may be loosened to adjust the position of the link 88 along the slot in the link 82 and comprises a means for adjusting the length of the stroke over which the grinding wheel is reciprocated.

In setting up the machine for grinding drills the length of the stroke of reciprocation of the grinding wheel 12 is adjusted by loosening the wing nut 92 to move the connection of the link 88 along the slot in the link 82. In grinding drills it is desirable that the entire peripheral grinding surface of the grinding wheel be utilized in sharpening a drill regardless of the diameter of the drill. Furthermore, it is desirable that the end of the drill always overlapithe peripheral grinding surface of the grinding wheel. Accordingly, when a drill of the particular diameter is to be sharpened the length of the stroke of reciprocation of the wheel 12 is adjusted so that the entire peripheral grinding surface of the wheel is utilized in the grinding operation while maintaining the drill in overlapping relationship with the peripheral grinding surface.

The reciprocation of the grinding wheel 12 in combination with the movement of the holder 38 whereby during the initial grinding operation the drill moves slowly but then moves faster in returning to the original position, has proven to provide an improved surface on drills thusly sharpened.

As will be understood from the foregoing description the assembly may be set up to grind a number of drills of a particular size in a manner that the operator need only index and substitute drills and whereby the plurality of drills may be sharpened in a very minimum amount of time with an improved ground surface.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A grinding machine assembly of the type utilized for grinding twist drills and the like, comprising:

a grinding wheel having a grinding surface and rotatable about a first axis;

drill holder means for supporting a drill or the like and oscillatable to move a drill into and out of engagement with said grinding surface;

first power means for moving said holder means faster in one direction than the other direction of oscillation and including means for providing a hesitation in the movement of said holder means as the latter is changing direction of movement while oscillating, and first adjustment means for adjusting the length of said hesitation.

2. A machine as set forth in claim 1 including means to adjust the amount of movement in said oscillation.

3. A machine as set forth in claim 1 including means supporting said grinding wheel for reciprocation parallel to said first axis, and second power means for reciprocating said grinding wheel.

4. A machine as set forth in claim 3 including second adjustment means for adjusting the length of the stroke of reciprocation of said grinding Wheel.

5. A grinding machine assembly of the type utilized for grinding twist drills and the like, comprising: a grinding wheel having a grinding surface and rotatable about a first axis; support structure; drill holder means for supporting a drill or the like and oscillatable to move a drill into and out of engagement with said grinding surface; first power means for moving said holder means faster in one direction than the other direction of oscillation; said holder means being rotatably supported by said support structure for oscillation in an are by said first power means; means for adjusting the amount of movement in said oscillation; means for providing a hesitation in the movement of said holder means as the latter is changing direction of movement while oscillating; said holder means including a shaft rotatably supported by said support structure, a drill support disposed at a first end of said shaft, a sleeve disposed on the second end of said shaft, first adjustment means for selectively allowing said sleeve to be rotated to a new position on said shaft for adjusting the length of said hesitation, a rod 5 extending radially from said sleeve, a first link rotated about a second axis, and a roller attached to said first link for engaging said rod to move the latter through an arc.

6. A machine as set forth in claim 5 including biasing means for urging said shaft to rotate in one direction.

7. A machine as set forth in claim 6 wherein said first adjustment means also includes an adjustable stop attached to said shaft for limiting the rotation of said shaft.

8. A machine as set forth in claim 7 wherein said first power means includes a first electric motor, said first link having a slot therein and extending radially relative to said first axis, said roller being adjustable along said slot for adjusting the arc of oscillation of said rod.

9. A machine as set forth in claim 8 including means supporting said grinding wheel for reciprocation parallel to said first axis, and second power means for reciprocating said grinding wheel.

10. A machine as set forth in claim 9 including second adjustment means for adjusting the length of the stroke of reciprocation of said grinding wheel.

.11. A machine as set forth in claim 10' including a first electric motor supporting said grinding wheel for rotating the latter, said means reciprocatively supporting said grinding wheel comprising slide means slidably supporting said first electric motor, said second power means including an auxiliary electric motor and linkage means operatively interconnecting said first electric motor and said auxiliary electric motor for reciprocating said first electric motor.

12. A machine as set forth in claim 11 wherein said linkage means comprises a second link rotated about a third axis by said auxiliary motor, a third link operatively connected at a first end thereof to said first electric motor and operatively connected at the second end thereof to said second link.

13. A machine as set forth in claim 12 wherein said means for adjusting the length of stroke of said grinding Wheel includes an element interconnecting said second and third links and movable to various positions along a slot in said second link, said slot being radially disposed in relation to said third axis.

References Cited UNITED STATES PATENTS 2,752,740 7/1956 Mouw 51-225 X 2,847,800 8/1958 Ingersoll 51-219 X 3,102,370 9/1963 Ribich 51219 X FOREIGN PATENTS 1,149,603 7/ 1957 France.

26,452 1911 Great Britain.

JAMES L. I ONES, 111., Primary Examiner US. Cl. X.R. 51-219 

